We are engaged in the first systematic efforts to exploit catalytic ketone/unsaturated moiety coupling via C-C activation. Our objective, in the proposed funding period, is to develop a Cut and Sew strategy for the efficient synthesis of bridged/fused ring systems via catalytic C-C activation, which includes 1) regular Cut and Sew: Rh- or Co-catalyzed intramolecular carboacylation with both strained and unstrained cyclic ketones; 2) decarbonylative Cut and Sew: catalytic intramolecular couplings between cyclic ketones and unsaturated moieties with CO extrusion. The research proposed is expected to provide a general and unified strategy to build complex skeletons, found in numerous natural products and drugs, from simple starting materials.